Citing newly-completed toxicology tests and information the two have provided, Round Lake Park Police Chief George Filenko says Melissa Best injected herself in the arm with heroin and died almost immediately in the efficiency apartment Sherry and Charles Best rented at the Crosslands Motel, on Illinois 41, in Waukegan.

But instead of making an immediate call to 911 to seek assistance, Sherry Best did nothing initially, Filenko said, eliminating any chance that her sister could be revived.

Instead, the first to try to render assistance to Melissa Best was her brother-in-law, who tried CPR unsuccessfully when he arrived at the apartment 20 minutes to 30 minutes later.

By that time, Filenko said, it was too late.

Filenko said that Sherry Best also admitted to using heroin that day.

Charles and Sherry Best soon decided to move the body and make it appear that she died elsewhere, Filenko said, for two reasons. He said Charles Best was on parole and feared he would be found in violation and jailed. And Filenko said the couple’s two children were already in custody of the Illinois Department and Family Services, and they feared that they would lose custody permanently.

Best allegedly told police that together, he and his wife carried Melissa’s body to her van and hid it in the back.

Charles Best allegedly said that he then drove the van to a Grayslake parking lot, where it was discovered 10 days later.

Sherry Best is charged with causing a drug-induced homicide, because she supplied the drugs; if convicted, she could face 15 to 30 years in prison.